PLATE XIII. 



Fro. 

 1, 2. Trigonia producfa, Lye. Inferior Oolite, Rodboroiigh Hill, near Stroud. 



(Page 60.) 



3, 4. „ „ Valves of the same species, exhibiting the hinge. Inferior 



Oolite, Oxfordshire. Coll. Royal School of Mines. 



5. „ v.-costata, Lye. Inferior Oolite, Cold Comfort, near Cheltenham ; 



specimen with the costse deformed. (Page 66.) 



6. „ conjimgens, Phil. Inferior Oolite, Millepore bed, near Scarborough. 



Also Plate X, figs. 5, 7, 8. (Page 62.) 



